AddJobHandleForProducer Question

Can someone please explain to me when this is needed and what it actually does?

From the doc I take it the AddJobHandleForProducer add some sort of dependance between the cmdBuffer and the job. Is this because each sys only has one cmdBuffer and it need to know when to playback the instructions for a particular job on that system? I just need someone to break this down a bit further for me

https://docs.unity3d.com/Packages/c...Unity.Entities.EntityCommandBufferSystem.html

 

Any time you pass a command buffer to a system you need to return the job handle to that the system that owns the command buffer (you can simply this and just pass the final jobhandle at end of system.)

This is required to ensure the jobs using the command buffer are complete before the barrier system runs.

 

So the cmdBuffer always runs at the end of the system, not between jobs in that system?

Also can you explain what you mean by barrier system since funnily enough im attempting to write one atm. The though was before I run my system that construct my procedural mesh i need to make sure all the systems gathering data is done and synced. I was under the impression I could do some cleanup and call inputDeps.Complete();

Code (csharp):

1.  
2.     /// <summary>
3.     /// Barries sync point for HexSphereBuild systems.
4.     /// </summary>
5.     //[UpdateAfter(typeof(HexSphereECSVisualizerSystem))]
6.     [UpdateAfter(typeof(HexSphereBuildEntitiesSystem))]
7.     public class HexSphereBuildBarrierSystem : JobComponentSystem
8.     {
9.  
10.         #region FLIELDS --------------------------------------------------------
11.  
12.         [ReadOnly] private EntityQuery eqVertexComp;
13.         [ReadOnly] private EntityQuery eqTriangleComp;
14.  
15.         #endregion
16.  
17.         #region METHODS --------------------------------------------------------
18.  
19.         /// <summary>
20.         /// Constructor for system.
21.         /// </summary>
22.         protected override void OnCreate()
23.         {
24.             base.OnCreate();
25.  
26.             //
27.             // Create Entity EntityQuery
28.             eqVertexComp = EntityManager.CreateEntityQuery(ComponentType.ReadOnly<VertexComponent>());
29.             eqTriangleComp = EntityManager.CreateEntityQuery(ComponentType.ReadOnly<TriangleComponent>());
30.  
31.         }
32.  
33.         #endregion
34.  
35.         #region MAIN THREAD ------------------------------------------------------
36.  
37.         protected override JobHandle OnUpdate(JobHandle inputDeps)
38.         {
39.             //
40.             // Remove hex vertex and triangle components so the system doen not run jobs
41.             EntityManager.RemoveComponent(eqVertexComp, typeof(VertexComponent));
42.             EntityManager.RemoveComponent(eqTriangleComp, typeof(TriangleComponent));
43.  
44.             //
45.             // Complete
46.             inputDeps.Complete();
47.  
48.             //
49.             // Cleanup
50.             eqVertexComp.Dispose();
51.             eqTriangleComp.Dispose();
52.  
53.             //
54.             // Return
55.             return inputDeps;
56.         }
57.  
58.         #endregion
59.  

 

No. It runs at the barrier system order, or when you call playback, not at the end of the system, at the end of the system you put dependencies by AJHFP, not more and not less. Buffer execution order depends on barrier place.

 

ok kind of getting it, so would any JobComponentSystem that inputDeps.Complete() be considered a barrier system. I think ive been too wild west shooting from the hip kinda stuff with Complete()